I tried to make a GFP fusion protein (my gene of interest was fused to the C terminal of GFP) but no expression occured...I tested the expression of the two proteins alone and individually they worked but not when fused together..I tried a linker between the two..still no luck...could it just be that the fusion protein is somewhat toxic to the cell (doesn't seem likely aye..especially if the 2 alones are ok)